1. Field of the Invention
This invention relates to preventive drugs for elastosis containing kojic acid or kojic acid .beta.-cyclodextrin inclusion complex as the effective ingredient, and their method of use.
2. Description of the Prior Art
The human dermis has collagen fiber bundles at its upper layer, and nearly parallel elastic fibers run along or across these collagen fiber bundles, which are evenly distributed over the entire dermal layer.
An increase in the number of elastic fibers and the consequent dissociation and breakage of collagen fiber bundles are often found in exposed parts of the skin of aged persons. This dermal abnormality, called elastosis, causes wrinkles on the skin; and is also known to be closely correlated to the occurrence of malignant carcinomas, particularly senile keratosis, keratoacanthoma, squamous cell carcinoma and basal cell carcinoma, because it is invariably found around these carcinomas.
No drug capable of curing or preventing elastosis has yet been discovered. Such a drug, if developed, would be of great use for protection of the skin and prevention of various skin cancers.
Kojic acid is a compound produced by Aspergillus oryzae or other kojic-acid-producing microorganisms, and many studies have been reported on its applications. These include skin-whitening cosmetics containing kojic acid (Japanese Patent Kokai No.3538/1978), antiinflamatory agents (Japanese Patent Publication No. 34446/1983), ultraviolet preventive agents (Japanese Patent Kokai No.157509/1980), and analgesic agents (Japanese Patent Kokai No.131915/1983).